1. Field of the Invention
The present invention relates to an electrophotographic image forming apparatus. Further, the present invention relates to a process cartridge, a developing device, a developer amount detecting system, and a developer container.
Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (such as an LED printer and a laser beam printer), and an electrophotographic facsimile apparatus. A process cartridge is formed by combining at least one of charging means, developing means, and cleaning means with an electrophotographic photosensitive member to compose an integral unit in the form of a cartridge that is detachably mountable to the main body of an electrophotographic image forming apparatus, or is formed by combining at least developing means with an electrophotographic photosensitive member to compose an integral unit in the form of a cartridge that is detachably mountable to the main body of an electrophotographic image forming apparatus.
2. Related Background Art
Conventionally, in electrophotographic image forming apparatuses using the electrophotographic image forming process, a process cartridge system has been widely adopted, in which an electrophotographic photosensitive member and process means acting thereon are combined into an integral unit in the form of a cartridge, which is detachably mountable to the main body of the image forming apparatus. In such a process-cartridge-type electrophotographic image forming apparatus, the user can replace the cartridge in person. In view of this, in some electrophotographic image forming apparatuses of this type, there is provided means for informing the user of consumption of the developer.
In a conventional developer amount detecting device, two electrode bars are provided inside the developer container of developing means, and a variation in capacitance between the two electrode bars is detected to thereby detect whether there is any developer in the container. Japanese Patent Application Laid-Open No. 5-100571 discloses a developer amount detecting device which includes, instead of two electrode bars, a developer detecting electrode member having two parallel electrodes which are arranged in parallel in the same plane at a predetermined interval and interdigitated with each other in a protrusion-and-recess-like fashion, the developer detecting electrode member being installed on the lower surface of the developer container. In this device, a variation in capacitance between the parallel electrodes arranged in a planar fashion is detected to thereby detect whether there is any developer in the container.
If it is possible to successively detect the remaining amount of developer in the developer container, the user will be advantageously enabled to see to what extent the developer has been consumed.
It is an object of the present invention to provide a developer container, a developing device, a process cartridge, a developer amount detecting system, and an electrophotographic image forming apparatus in which it is possible to successively detect the remaining amount of developer.
Another object of the present invention is to provide a developer container, a developing device, a process cartridge, a developer amount detecting system, and an electrophotographic image forming apparatus in which it is possible to successively detect the remaining amount of developer with high accuracy.
Still another object of the present invention is to provide a developer container, a developing device, a process cartridge, a developer amount detecting system, and an electrophotographic image forming apparatus in which it is possible to successively detect the remaining amount of developer in a stable manner.
A further object of the present invention is to provide a developer container, a developing device, a process cartridge, a developer amount detecting system, and an electrophotographic image forming apparatus in which it is possible to successively detect the remaining amount of developer at low cost.
A further object of the present invention is to provide an electrophotographic image forming apparatus, a process cartridge, a developing device, a developer amount detecting system, and a developer container which are provided with a low-cost, high-accuracy developer amount detecting means, which makes it possible to obtain a stable detection value as the developer in the developer container is consumed and to measure the remaining amount thereof with high accuracy.
A further object of the present invention is to provide a developer container, a developing device, a process cartridge, a developer amount detecting system, and an electrophotographic image forming apparatus comprising:
(a) a first detecting member which is an electrode member having input-side and output-side electrodes formed in parallel in the same plane at a predetermined interval and adapted to detect the capacitance between the electrodes and which has a measurement-side electrode that is in contact with developer and a reference electrode that is out of contact with developer;
(b) a developer removing member for removing developer adhering to a detection region of the first detecting member; and
(c) a second detecting member consisting of a conductive member and adapted to detect capacitance between it and a developer bearing member,
wherein the first detecting member detects the developer amount partway from the start of use of the developer container, and then the second detecting member detects the developer amount.
These and other objects, features and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.